This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A117163 #7 Mar 30 2012 18:37:44 %S A117163 0,1,-1,-2,0,-1,1,0,1,-1,1,2,0,-3,2,2,0,-1,0,1,0,-1,1,0,0,-1,1,3,0,-1, %T A117163 -1,-2,0,0,0,2,0,-2,2,2,0,2,-1,0,-2,-2,1,-2,-1,0,1,3,0,-1,-1,1,1,0,1, %U A117163 -1,0,-1,0,1,0,2,-1,0,0,3,-1,-2,0,-2,0,3,-2,1,-1,-4,-1,-1,1,-3,0,1,2,2,0,2,-1,3,2,-1,1,4,0,1,-1,1,0,-1 %N A117163 Column 2 of triangle A117162; equals the Moebius transform of A008683 (column 1 of A117162) preceded by a zero. %C A117163 The inverse Moebius transform of A117164 (column 3 of A117162) equals this sequence preceded by a zero. %F A117163 Equals the Moebius transform of column 1 preceded by a zero: %F A117163 [0,1,-1,-2,0,-1,1,0,...] = Moebius([0, 1,-1,-1,0,-1,1,-1,...]). %Y A117163 Cf. A117162, A112682, A008683 (column 1); A117164 (column 3). %K A117163 sign %O A117163 1,4 %A A117163 _Wouter Meeussen_ and _Paul D. Hanna_, Mar 05 2006